First Test                              

After our trailer was completed, the next step was to test the accuracy of it. This was done a couple of different ways. Our first test for the machine was with a 1.125” diameter steel bar. This was used because steel has a consistent Modulus of Elasticity, usually with a value of 28,000 to 31,000 ksi. The bar was loaded just as a log would be and the test was performed. We obtained a value of approximately 31,000 ksi. This was the first time we knew our machine was on the right track, but because the exact Modulus of Elasticity of that specimen was not known we needed to conduct further tests.

Side by Side Testing

The next step of testing consisted of bringing our trailer in to the lab where the current testing apparatus is. The machines were set side by side and we made sure each machine had consistent testing conditions such as support span lengths. From there a log was placed on to the lab machine and tested up to three times. The placement of the log was marked to ensure the log was being tested on the same spot each time. Then the log would be moved to the other machine and placed so that it would be tested in that same position. The log was tested three times again and the values were compared. This process was repeated for numerous logs.

The values of the machines varied slightly. Generally, the value of Modulus of Elasticity obtained by our machine was about 1000 ksi higher than the value obtained from the lab machine. While the values were slightly off from one another, our machine produced very consistent values for each of the three tests performed on each log. Our values would be within 100 ksi of each other, while the current machine’s values ranged up to 1000 ksi. This gave us a lot of confidence in our machine and something to be proud of in what we designed and built.